The present invention relates to a coil winding machine for winding the coil of the core of a dynamoelectric machine such as a generator or a motor and, more particularly, to a coil winding machine suitable for use in winding coils around a core in which the angle formed between the neutral axes of a pair of slots for receiving the same coil around the axis of the core is around 90.degree. or smaller. This angle will be referred to as "intersecting angle", hereinafter.
In dynamoelectric machines, a cylindrical member such as, for example, a rotor core is provided in its peripheral surface with a required number of slots which extend in parallel with the axis of the rotor core, the slots being adapted to receive the wires for forming the coils. In some cases, it is required that the intersecting angle formed between a pair of slots for receiving the wires of the same coil is 90.degree. or smaller.
If the core has a sufficiently large intersecting angle between the pair of slots, it is allowed to make the coil winding such that the wires extend along the shortest path on each axial end surface of the core, thereby to minimize the length of each coil. However, in case where the intersecting angle is as small as 90.degree. or less, the end coil on each axial end surface will inconveniently overlie the axial end opening of the slot or slots between the pair of slots in which the coil is formed, if the end coil on each axial end surface of the core is formed along the shortest path. In such a case, it is not possible to correctly place the required number of wires in those slots between the pair of slots receiving the coil. In addition, the small intersecting angle of 90.degree. or less causes a tendency that the wires in each of the pair of slots are inconveniently accumulated on the side wall of the slot closer to the other slot of the pair, so that the wires are placed in each slot only at a small rate of occupation of the slot volume.
The following method has been proposed as a measure for mechanically winding coils at a small intersecting angle while obviating the above-described problems.
According to this method, an arcuate end guide for locating the end coil is disposed at each axial end of the core, and the wire continuously extracted from the flyer of the coil winding machine is wound round the end guide. The wire is slided along the end guide due to its tension, so that the end coil is formed near the center of the end surface of the core.
This method eliminates the aforementioned problem of the closure of end opening of intermediate slot by the end coil. In addition, since the end coil is pulled radially inwardly, the wires in each slot are pulled and accumulated on the bottom of the slot to improve the rate of occupation of the slot volume.
This method, however, poses the following problems. Namely, since the wires of the end coil are accumulated on the end guide and concentrated to the narrow region near the axis of the core, the amount of projection of the end coil from the end surface and, hence, the length of the coil are inconveniently increased. In order to reduce the projection amount of the end coil from the end surface of the core, it is necessary to conduct a shaping work to suitably shape the end coils after the winding of all coils. This shaping is extremely difficult to conduct and can be made only at an extremely low efficiency of work, because the end coils are concentrated to the restricted area.